Air intake noise reduction apparatus for automotive vehicle

Abstract

An air intake noise reduction apparatus is provided which can effectively reduce air intake noise even with simple construction requiring a small number of components. Four air intake passages 24, 25, 26, 27 which each have different passage lengths are formed by connecting an upper wall 17 and a lower wall 18 of an air intake noise reduction duct 11 which are flattened in a vertical direction with three partition walls 21, 22, 23. Air intake noise can be reduced by making pulsating air interfere with one another which is generated in the plurality of air intake passages 24, 25, 26, 27 which each have the different passage lengths in such a manner as to have different phases shifted from one another. In addition, since the partition walls function as a reinforcement rib, the rigidity of the air intake noise reduction duct 11 can be enhanced. Moreover, since the partition walls are formed in such a manner as to extend along an intake air flow direction, increase in intake air resistance can be suppressed to a minimum level.

What is claimed is:  
     
       1. An air intake noise reduction duct for an automotive vehicle for reducing air intake noise with an air intake noise reduction duct ( 11 ) for inducting air into an engine of said automotive vehicle, wherein 
       a plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) which each have different passage lengths are formed by partitioning said air intake noise reduction duct ( 11 ) with partitioned walls ( 21 ,  22 ,  23 ), wherein the plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) direct air into the engine and have identical cross sectional areas and said partition walls ( 21 ,  22 ,  23 ) extend to identical positions on a downstream side of the air intake noise reduction duct ( 11 ).  
     
     
       2. The air intake noise reduction duct according to  claim 1 , wherein said air intake noise reduction duct ( 11 ) is partitioned by said partition walls ( 21 ,  22 ,  23 ) which extend along an intake air flow direction. 
     
     
       3. The air noise reduction duct according to  claim 1 , wherein said plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) which each have different passage lengths are formed by connecting opposed walls ( 17 ,  18 ) each having a largest surface area of a flat portion provided in said air intake noise reduction duct ( 11 ) with said partitioned walls ( 21 ,  22 ,  23 ) extending along an intake air flow direction. 
     
     
       4. The air intake noise reduction duct according to  claim 1 , wherein said plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) which each have different passage lengths are formed by partitioning a curved portion provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ) extending so as to conform to a curved configuration of said curved portion. 
     
     
       5. The air intake noise reduction duct according to  claim 4 , wherein the length of said partition walls ( 21 ,  22 ,  23 ) is made shorter as said partitioned walls are situated more inwardly of said curved portion in a curved direction. 
     
     
       6. The air intake noise reduction duct according to  claim 4 , wherein said plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) are formed by connecting opposed walls ( 17 ,  18 ) each having a largest surface area of a flat portion provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ) extending along an intake air flow direction. 
     
     
       7. The air intake noise reduction duct according to  claim 1 , wherein the intake air flow direction and the direction of said partition walls ( 21 ,  22 ,  23 ) are made to intersect with each other at an entry portion of said air intake noise reduction duct ( 11 ). 
     
     
       8. The air intake noise reduction duct according to  claim 7 , wherein said plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) are formed by connecting opposed walls ( 17 , 18 ) each having a largest surface area of a flat portion provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ). 
     
     
       9. The air intake noise reduction duct according to  claim 1 , wherein an opening end ( 28 ) of said air intake noise reduction duct ( 11 ) is shaped so as to meet configurations of a mating member ( 100 ). 
     
     
       10. The air intake noise reduction duct according to  claim 9 , wherein said mating member is one of a vehicle body and an auxiliary machine. 
     
     
       11. The air intake noise reduction duct according to  claim 9 , wherein said plurality fair intake passages ( 24 ,  25 ,  26 ,  27 ) are formed by connecting opposed walls ( 17 ,  18 ) each having a largest surface area of a flat portion provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ) extending along an intake air flow direction. 
     
     
       12. The air intake noise reduction duct according to  claim 1 , wherein said plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) which each have different passage lengths are formed by connecting opposed walls ( 17 ,  18 ) each having a largest surface area of a flat portion provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ). 
     
     
       13. An air intake noise reduction duct for reducing intake noise of air inducted into an engine of an automotive vehicle, wherein 
       a plurality of intake passages ( 24 ,  25 ,  26 ,  27 ) which each having different passage lengths are formed by partitioning said air intake noise reduction duct ( 11 ) with partition walls ( 21 ,  22 ,  23 ), and by connecting flat opposed walls ( 17 ,  18 ) each having a largest surface area of flat portions provided in said air intake noise reduction duct ( 11 ) with said partition walls ( 21 ,  22 ,  23 ),  
       characterized in  
       that the air intake noise reduction duct is made of a single member of synthetic resin, and  
       that the plurality of intake passages ( 24 ,  25 ,  26 ,  27 ) separately open directly to the outside of the air intake noise reduction duct ( 11 ), wherein the plurality of air intake passages ( 24 ,  25 ,  26 ,  27 ) direct air into the engine and have identical cross sectional areas and said partition walls ( 21 ,  22 ,  23 ) extend to identical positions on a downstream side of the air intake noise reduction duct ( 11 ).